1. Field of the Invention
The present invention relates to an apparatus for transporting parts, and particularly relates to an apparatus for transporting parts which separates the first part in a row of parts being transported from the second part in this row.
2. Description of the Related Art
Regarding apparatuses for transporting small parts such as chip parts, an apparatus is known wherein an endless belt comprises the bottom of a transporting groove through which parts are guided, and wherein the parts are transported by means of intermittent driving of this belt (see Japanese Unexamined Patent Publication No. 8-48419). In the case of this apparatus, a mechanism is provided for separating the first part in the row on the belt from the second part in the row, so as to allow the first part in the row to be extracted therefrom. This separating mechanism acts so that a stopper is brought into contact with the front-most end of a guiding groove at the time that the parts on the belt move forward with the forward motion of the belt, the first part is stopped at a certain position, and upon the first part coming into contact with the stopper so that motion of all parts is stopped, the second part is held in the same position by a holding pin while the stopper is opened forwards so as to allow the first part to proceed forward while remaining in the state of being attached by a permanent magnet on the stopper, thereby forcibly forming a gap between the first part and the second part.
However, this method in the above separating mechanism involves stopping the movement of all parts, attaching the first part by a permanent magnet provided in the stopper, and pulling this part forward by magnetic force, meaning that the parts cannot be separated in the event that the part is formed of a non-magnetic material, or that debris or the like is on the part such that magnetism does not effectively work. Also, friction occurs between the part and belt at the time of extracting the first part, so there is the possibility that the attachment between the permanent magnet and the part may be separated. Thus, such an arrangement has the problem of being unreliable.
Accordingly, it is an object of the present invention to provide an apparatus for transporting parts, wherein the first part and second part can be separated in a sure manner even in the event that the parts are non-magnetic material, and wherein ease of extracting of the first part is facilitated.
In order to achieve the above object, a part transporting apparatus comprises: a guiding groove for lining up parts in one row and guiding the parts; a transporting member which is provided at the base of the guiding groove and transports the parts in a forward direction by itself moving forwards and backwards along the groove; driving means for reciprocally driving the transporting member in the forward and backward directions; a stopper which operates so as to open and close in the width direction of the guiding groove, and hold the second part from the front of the row of parts being transported on the upper plane of the transporting member; and synchronizing means for opening and closing the stopper synchronously with the reciprocal forward and backward movement of the transporting member; wherein, once the stopper holds the second part, the transporting member moves forward by a certain distance, thereby separating the first part in the row and the second part.
FIGS. 1A through 1E illustrate the operation principle of the part transporting mechanism according to the present invention.
FIG. 1A is the initial position, with both sides of the parts P being guided by a guiding groove (not shown), and thereby arrayed in a single row. A transporting member M capable of moving forwards and backwards is provided to the bottom plane of the guiding groove. The parts P ride on the upper surface of the transporting member M, and an opened stopper S is located by the side of the first part P1. In this drawing, the stopper S is positioned above the parts P, but in actual use is positioned to the side of the parts P (in the direction perpendicular to the surface of the drawing).
FIG. 1B shows the transporting member M in a state of having been moved forward by one pitch. At this point, the stopper S is operated in the closing direction, the second part P2 is pressed against the inside of the guiding groove and thus held, thereby preventing forward movement of the second and subsequent parts.
FIG. 1C shows the transporting member M in a state of having been moved further forward. Here, the first part P1 moves forward with the forward movement of the transporting member M, but the second and subsequent parts P are restrained by the stopper S, so relative slippage is generated between the transporting member M and the second and subsequent parts P. Consequently, a gap xcex4 is generated between the first part P1 and second part P2.
FIG. 1D shows an extracting device K such as a mounter or the like being used to extract the first part P1. At this time, a gap xcex4 is provided between the first part P1 and second part P2, so there is no danger of the second part P2 being accidentally extracted.
FIG. 1E shows the transporting member M in a state of having been moved backwards. At this point, some sort of means is provided to prevent the parts P from moving backwards with the transporting member M. Consequently, relative slippage is generated between the transporting member M and the parts P, so the transporting member M alone moves forward and the parts P are maintained at the progressed position.
Repeating the operation shown in FIGS. 1A through 1E intermittently transports the row of parts P forward, and sequentially extracts the first part P1 one at a time.
Regarding the method of transporting the parts in one direction with the transporting member, it is preferable that friction is used. That is, the driving means may drive the transporting member in a reciprocal manner such that the speed of moving in the backward direction is greater than the speed of moving in the forward direction. The speed of moving in the forward direction is a speed at which holding friction acts between the transporting member and the parts disposed upon the upper surface thereof; and the speed of moving in the backward direction is a speed at which the friction between the transporting member and the parts disposed upon the upper surface thereof is essentially broken. With such an arrangement, the parts can be transported in one direction simply by reciprocal driving of the transporting member, so the transporting mechanism can be simplified, and further, the parts are not restrained, so there is little damage inflicted upon the parts. Incidentally, the term xe2x80x9cthe friction . . . is essentially brokenxe2x80x9d includes not only speeds at which friction does not act at all, but also speeds at which the parts do not actually move backwards even if friction does act.
Also, the synchronizing means may comprise: a first groove provided in a diagonal manner to the tip portion of the transporting member; a second groove provided in a vertical manner on the inner surface of a fixing member for guiding the side of the transporting member; a rolling member fitted to the first groove and the second groove so as to straddle the space therebetween; an inclined plane formed on the stopper, coming into contact with the rolling member; and a spring pressing for the stopper in the direction of holding parts. With this arrangement, the rolling member moves vertically along the first and second grooves owing to the reciprocating action of the transporting member in the forward and backward directions, and the rolling member moves along the inclined plane provided to the stopper, so that the stopper reciprocally moves in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts.
In this case, the rolling member is used to comprise the synchronizing means, so movement is smooth and the mechanism is durable. Also, the stopper is moved synchronously with the movement of the transporting member, so the timing between holding the second part and forward movement of the transporting member is easily synchronized, and the reliability of operating is high.
Also, the synchronizing means may comprise: a contacting portion provided to the transporting member; an inclined plane formed on the stopper, the portion thereof coming into contact with the contacting portion in the forward and backward directions; and a spring for pressing the stopper in the direction of holding parts. With this arrangement, the contacting portion moves along the inclined plane of the stopper owing to the reciprocating action of the transporting member in the forward and backward directions, so that the stopper reciprocally moves in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts.
Such an arrangement reduces the number of part and simplifies the structure.
Further, the synchronizing means may comprise: an inclined plane provided on the transporting member in the forward and backward direction; a contacting portion formed on the stopper, coming into contact with the inclined plane member; and a spring pressing for the stopper in the direction of holding parts. With this arrangement, the contacting portion of the stopper moves over the inclined plane owing to the reciprocating action of the transporting member in the forward and backward directions, so that the stopper reciprocally moves in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts.
Such an arrangement also reduces the number of part and simplifies the structure, as with the above arrangement.
Also, the synchronizing means may comprise: a first groove provided in a diagonal manner to the tip portion of the transporting member; a second groove provided in a vertical manner on the inner surface of a fixing member for guiding the side of the transporting member; and a rolling member fitted to the first groove and the second groove so as to straddle the space therebetween. The stopper itself may be formed of a material having spring-like properties in the direction of holding parts. With this arrangement, the rolling member moves vertically along the first and second grooves owing to the reciprocating action of the transporting member in the forward and backward directions, and the rolling member moves along the inclined plane provided to the stopper, so that the stopper reciprocally moves in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts.
This arrangement is of the same configuration as the synchronizing mechanism according to an earlier arrangement, but the stopper itself is formed of a spring-like member, so the spring is unnecessary, and thus the mechanism can be simplified.
Also, the stopper may be provided to one side of the guiding groove, with the stopper reciprocally moving in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts. Or, the stopper may be provided to both sides of the guiding groove, with the stopper reciprocally moving in the width direction of the guiding groove, thereby holding the second part from the front of the row of parts.